This invention relates generally to core holders for use in the measuring of certain characteristics and the testing of the effect of various fluids on cores of geological formations of the earth or other similar cylindrical porous samples at pressures greater than atmospheric pressure and temperatures equal to or greater than room temperature, and, more particularly, to such a core holder with means for simultaneously subjecting such a sample to axial and radial pressures of unequal magnitude and the capability of being contained in a conventional laboratory oven during testing to simulate in situ conditions of the formation from which the core was taken.
It is common practice in the petroleum industry to remove core samples from subsurface geologic formations for testing. Typically, a core barrel is used to remove cores at intervals as a well is drilled. Some core samples are used for routine tests of the porosity, permeability and other important characteristics of a petroleum producing formation. Other core samples are used for waterflooding, enhanced recovery, formation damage or other special tests.
It is usually desirable for both routine and special tests of core samples to be conducted at pressures simulating those encountered in the subsurface geologic formations from which the core samples were removed. Usually, such tests are conducted at room temperature. However, it is sometimes desirable for such tests to be conducted at temperatures greater than room temperature. Accordingly, it is desirable to have core holders which permit such tests to be conducted at various pressures within a range of pressures greater than atmospheric pressure and temperatures within a range of temperatures greater than room temperature.
It is desirable to have a core holder with means for simultaneously subjecting a core sample to axial and radial pressures of unequal magnitude which is capable of being contained in a conventional laboratory oven during testing. It is also desirable to have such a core holder which can accommodate a varying number of fluid supply lines, electrical wires and the like necessary for various routine and special tests. It is not believed that the prior art provides such a core holder.